JP2654565B2 - Driving circuit of liquid crystal device using nonlinear resistive film - Google Patents

Description

The present invention relates to a driving circuit for a liquid crystal element using a non-linear resistive film used in a display device, an optical shutter, and the like.
The present invention relates to a liquid crystal element driving circuit using a nonlinear resistance film with a simple configuration using a TN type liquid crystal element driving circuit.

[Summary of the Invention]

In a driving circuit of a liquid crystal element using a non-linear resistance film,
It is driven using the drive circuit of a normal TN type liquid crystal element as it is. The drive circuit of the TN type liquid crystal element has a display data inversion circuit and a non-selection circuit for deselecting half of one scanning time. It is configured by adding a selection signal generation circuit.

[Conventional technology]

There are two methods of driving a liquid crystal device using a non-linear resistive film: a voltage averaging method that uses the driving method of a TN liquid crystal device as it is, and phase modulation that suppresses fluctuations in the liquid crystal interlayer voltage due to display and other conditions. There is a law. Conventionally TN
Drive by the voltage averaging method as it is using the liquid crystal element drive circuit, or store the lighting data and the inverted data of the lighting data in the display memory on the controller side, and
A liquid crystal element using a non-linear resistance film by the phase modulation method, in which the lighting data is output in the half period, and the inverted data of the lighting data is output from the drive circuit on the signal electrode side and displayed while the remaining half period is a non-selection period. Was driving. In the driving method based on the phase modulation method, the number of display memories is increased, and the circuit configuration on the controller side is increased, resulting in an increase in cost.

FIG. 3 shows a driving circuit for a liquid crystal display device having a nonlinear resistive film according to the prior art. 10 is a signal electrode drive circuit, 20 is a scan electrode drive circuit, 30 is a liquid crystal display element using a non-linear resistive film, 40 is a drive power supply circuit, 50 is display data, 60 is a control line, 70
Is the power supply.

[Problems to be solved by the invention]

An object of the present invention is to solve the problems of an increase in the number of display memories on the controller side and an increase in cost in a drive circuit of a liquid crystal element using a nonlinear resistance film.

[Means for solving the problem]

A display data inverting circuit for inverting display data and a non-selection signal generating circuit for generating a signal for inverting the display data are provided between the controller and a driving circuit of a liquid crystal element using the non-linear resistance film.

〔Example〕

When driving and displaying a liquid crystal element using a nonlinear resistance film,
The contrast fluctuates due to the fluctuation of the effective voltage, and deterioration of display quality has been a problem.

The present invention provides a driving circuit for a liquid crystal element in which the fluctuation of the effective voltage is suppressed.

FIG. 1 shows a configuration of a driving circuit of a liquid crystal element using a non-linear resistance film according to the present invention. The signal electrode drive circuit is, for example,
SED1600FOA (Suwa Seikosha) and scanning electrode drive circuit SE
Use D1610FOA (Suwa Seikosha). FIG. 2 shows the time chart of FIG. The signal electrode side latch signal (LOAD) causes the signal electrode drive circuit to latch the display data (D3 to Dφ) for each horizontal line and, at the same time, triggers the J / K flip-flop 2 of the non-selection signal generation circuit. The J / K flip-flop 2 operates as a toggle flip-flop because the J and K terminals are connected to the Vcc level, and each time the signal electrode side latch signal (LOAD) falls, the non-selection signal in the time chart of FIG. (1) is generated. When the non-selection signal (1) is at the “L” level, the non-selection signal terminal (▼) of the scan electrode drive circuit is driven, and the output (7) of the scan electrode drive circuit has a non-select waveform. The non-selection signal (1) goes to the display data inverting circuit and the non-selection signal (1)
Is at "H" level, the display data (D3 to Dφ) is inverted and goes to the signal electrode drive circuit. The inverted output terminal () of the J / K flip-flop and the signal electrode side latch signal (LOAD) are input to the AND gate (3) to generate the scan electrode side latch signal (5), and the shift of the scan electrode drive circuit is performed. Drive the clock terminal (YSCL). When the frame signal (FRM) and the scan electrode side latch signal (5) overlap, the common electrode Y of the liquid crystal display element (MSI panel) using the non-linear resistive film starts from the falling point of the scan electrode side latch signal (5). going to drive in order from ₁ to Y _m. Signal electrode side latch signal (LO
AD) drives the latch terminal (LP) of the signal electrode drive circuit,
In the fall time of the signal electrode side latch signal (LOAD), and the latch on the display data shifted by the clock signal (CP) (D3~Dφ), drives the segment electrode X ₁ to X _n of the MSI panel. The signal electrode side latch signal (LOAD) is generated for each horizontal dot number (n dots) of the MSI panel. On the other hand, the scanning electrode side latch signal (5) is generated every two horizontal dots. The first horizontal dot period of the two horizontal dots is the second horizontal dot period.
As is clear from the time chart of FIG. 7, since the non-selection signal (1) is at the "H" level, the signal electrode display data (4) is inverted and input to the signal electrode drive circuit, and during the latter half of the two horizontal dot count ( When the non-selection signal (1) is at “L” level,
That is, the output (7) of the scan electrode driving circuit appears in the output (6) of the signal electrode driving circuit during the period of the non-selection waveform, and the non-selection signal waveform is applied to the MSI panel. In the latter half period of the two horizontal dot numbers, the display data (D3 to Dφ) is input to the signal electrode drive circuit without being inverted, so the first half period of the next two horizontal dot numbers (the time chart in FIG. 2). 2)
Correctly displayed from. Thereafter, the non-selection and selection states are repeatedly displayed.

By driving the MSI panel with such a driving circuit, it is possible to suppress the fluctuation of the effective voltage of the pixel due to the state of the pixel, and to provide a driving circuit of the MSI panel free from uneven contrast. Further, there is an advantage that a normal TN type drive circuit can be used as it is, and no specially complicated circuit is required.

〔The invention's effect〕

According to the present invention, it is possible to configure a drive circuit for an MSI panel by a phase modulation method using a normal TN drive circuit without increasing the display memory, and it is also possible to prevent an increase in cost on the controller side. The present invention can be used for various liquid crystal elements such as a display device and an optical shutter such as a printer shutter.

[Brief description of the drawings]

FIG. 1 is a block diagram of a liquid crystal display element driving circuit using a non-linear resistance film, FIG. 2 is a time chart of FIG. 1, and FIG. 3 is a driving circuit of a conventional non-linear resistance liquid crystal display element. Dφ to D3 Display data CP Clock signal DF AC inversion signal FRM Frame signal LOAD Signal electrode side latch signal MSI panel Liquid crystal display element with non-linear resistive film 1 Non-selection signal 2 ... J / K flip-flop 3 ... AND gate 6 ... Output of signal electrode drive circuit 7 ... Output of scan electrode drive circuit

Claims (1)

(57) [Claims] 1. A drive circuit for a liquid crystal element using a non-linear resistive film, comprising: a J / K flip-flop to which a signal electrode side latch signal is input and which generates a non-selection signal; An AND gate receiving a signal electrode side latch signal and outputting a scan electrode side latch signal; a display data inverting circuit for inverting display data according to the non-selection signal; and signal electrode display data from the display data inverting circuit. A signal electrode drive circuit for receiving and driving a signal electrode; a scan electrode drive circuit having an input terminal to which the non-selection signal is input and an input terminal to which the scan electrode side latch signal is input; A liquid crystal element using a non-linear resistance film, comprising: a liquid crystal element; and a drive power supply circuit for supplying a voltage to the signal electrode drive circuit and the scan electrode drive circuit. Child drive circuit.